The cable news networks have seen a dramatic increase in viewers as a result of the Iraq war.

In the fierce battle for viewers among the competing television news organisations, it has been Fox News Channel, the cable network controlled by Rupert Murdoch's News Corporation, that has been the big winner.

Fox News, which puts a patriotic spin on the news and became the largest cable news channel in 2002, increased its number of viewers by 300% to average 3.3 million daily viewers during the conflict.

It was a remarkable achievement for the channel, which was only started in 1996.

CNN was second, with 2.65 million, while rival MSNBC, which is owned by the television network NBC, had 1.4 million - the biggest gain, in percentage terms (350%), for the smallest of the cable news stations.

MSNBC copied many features of Fox News, adding conservative commentators, a US flag on screen, and a special section called "America's Bravest" where viewers could send pictures of their loved ones serving in the armed forces in Iraq.

Networks suffer

CBS newsman Walter Cronkite influenced a president

The big losers, meanwhile, were the TV network's nightly news programmes, which actually lost two million viewers - or 10% - during the same period, after an initial increase in the first few days.

Only NBC, which may have benefited from cross-promotion from its cable channel, was able to stem the decline.

In previous wars, viewers had turned to the trusted anchors like CBS's Dan Rather, ABC's Peter Jennings, and NBC's Tom Brokaw, to interpret the news.

Indeed, it was the comments of former CBS News anchor Walter Cronkite during the Vietnam War that helped convince President Lyndon Johnson that he should not stand for office in 1968.

This was reporters' war, not an anchors' war; this involved a series of very profound individual vignettes

Andrew Heyward, president, CBS News

But the president of CBS News, Andrew Heyward, said the new practice of embedding reporters with military units was a very important change this time around.

"This was reporters' war, not an anchors' war; this involved a series of very profound individual vignettes," he said, which were upsetting to some viewers.

The mainstream networks point out that they still have a total of 28 million viewers, as opposed to between seven million and eight million for the cable news stations.

But this time, CBS's Dan Rather only reached Baghdad in a convoy after the fighting was over.

The dilemma of the networks was reflected in their agonising - during the first weekend of the war - over whether to run 24-hour coverage of the conflict, or to show a popular college basketball tournament which might get higher ratings.

Basketball, inevitably, finally won.

The "Fox effect"

There was also a fierce battle over embedded and other correspondents between the networks.

Too many retired officers commenting?

The star CNN war correspondent of the 1991 Gulf War, Peter Arnett, who was again in Baghdad, this time for National Geographic and MSNBC, was sacked after appearing on Iraqi television.

Fox News' celebrity presenter Geraldo Rivera was temporarily removed from his unit of the 101st Airborne Division for giving away their position.

Meanwhile, Bush administration officials and military leaders were highly critical of the commentary provided on many news programmes by retired generals, such as CNN's Wesley Clark, as too pessimistic.

Defence Secretary Donald Rumsfeld said that there were too many "retired military officers" who opined on television and newspapers "that constantly, you know, blare big headlines of 'Henny Penny: The Sky Is Falling,' 'It's Just Terrible,' or 'Isn't It Awful?' "

The fact that the war was so extensively covered on cable - and on the internet - has significantly shortened the "news cycle", so that coverage swung very quickly between optimism and pessimism as events unfolded.

There is a long-standing tradition of middle-of-the-road journalism that is objective and fair - I would hate to see that fall victim to the Fox effect

Andrew Heyward

But after years in which there had been criticism - on radio talk shows and the internet - of the "liberal bias" of the media, this was the moment in which those critics moved into the mainstream, and are now being closely watched by their rivals.

"I certainly think all the news people are watching the success of Fox," Mr Heyward said.

"There is a long-standing tradition in the mainstream press of middle-of-the-road journalism that is objective and fair. I would hate to see that fall victim to the Fox effect."

The highly partisan atmosphere of the news, and the sometimes defensive tone of the main networks, also contributed to an increase in the figures for alternative sources of the news, such as National Public Radio, a small state-funded broadcaster.